In recent years, there has been significant and growing interest in the motor vehicle and other industries in the use of various polymer-based foams to stiffen, reinforce, seal or acoustically modify hollow members such as door assemblies, pillars, rocker panels and the like. Quite often, such polymer-based foams are used in combination with carriers which help to control and direct the expansion of the expandable resins used to make such foams and which themselves can assist in achieving the desired structural and acoustic characteristics. However, such carriers typically have to be custom designed for particular end-use applications. Moreover, the amount of expandable resin used generally is considerable, which further adds to the cost of production.
Thus, there remains a need for flexible, versatile universal designs which can be applied to a wide variety of applications and which utilize expandable resins in a cost-effective way to achieve a desired level of performance.